The present disclosure relates to an antistatic agent for thermoplastic resin capable of imparting conductivity to thermoplastic resin compositions and an antistatic resin composition containing this antistatic agent for thermoplastic resin.
In general, though plastic materials are widely used because of excellent characteristics thereof, they are electrically insulating and have such properties that they are easily charged with static electricity. For that reason, dust attaches to a plastic molded article, whereby its appearance is impaired. Also, when the plastic material is used for cases or parts of electric or electronic devices, there may be the case where malfunctioning of the device or a fault of electronic parts such as IC is caused due to discharge of static electricity. For that reason, there have hitherto been developed various technologies regarding the prevention of electrification of plastics. For example, it is generally carried out to add an antistatic agent of a surfactant type to a plastic. However, in such a method, though short-term antistatic properties are excellent, the antistatic properties cannot be kept for a long period of time, and therefore, there is involved a problem regarding the durability.
Also, there is a method for kneading a conductive inorganic material such as a carbon fiber and carbon black into a plastic material for the purpose of imparting persistent antistatic properties. In this method, since the plastic material is colored by a black color of the foregoing carbon fiber or the like, there is involved a problem that the color tone of a plastic material which can be used is limited to the black color.
In addition to this, there is disclosed a method for using a sulfonated polystyrene jointly with an organic base or a silicone (see, for example, JP-A-9-188873, JP-A-10-140142, JP-A-10-231328, JP-A-10-316960, JP-A-11-189769, JP-A-11-23655 and JP-A-200341133). It cannot be said that the sulfonated polystyrene which is used in this method is thoroughly satisfactory in view of the antistatic effect. Also, the sulfone group is introduced into the whole of the resin, and there is a defect that blocking between the resins is easily generated by moisture absorption.
Therefore, it is desirable to provide an antistatic agent thermoplastic resin which is excellent in an antistatic effect, is able to reveal antistatic properties for a long period of time and is excellent in durability and an antistatic resin composition containing this antistatic agent for thermoplastic resin.
Also, it is desirable to provide an antistatic agent for thermoplastic resin which is excellent in both handling and antistatic performance as compared with existing antistatic agents for thermoplastic resin and an antistatic resin composition containing this antistatic agent for thermoplastic resin.